feat: add a config option to bypass mime content type sniffing (#60)

Fixes the issue of publishing all commit since inception (see: goreleaser/goreleaser#990)

.github/workflows/release.yml

@@ -22,10 +22,8 @@ jobs:
 
     - name: Checkout code
       uses: actions/checkout@v2
-
-    # So GoReleaser can generate the changelog properly
-    - name: Unshallowify the repo clone
-      run: git fetch --prune --unshallow
+      with:
+        fetch-depth: 0
 
     # https://github.community/t5/GitHub-Actions/How-to-get-just-the-tag-name/m-p/32167/highlight/true#M1027
     - name: Print Go version and environment

.goreleaser.yml

@@ -53,7 +53,7 @@ release:
   github:
     owner: hacdias
     name: webdav
-  draft: true
+  draft: false
   prerelease: auto
 
 dockers:

README.md

@@ -57,6 +57,8 @@ users:
       - regex: false
         allow: false
         path: /some/file
+      - path: /public/access/
+        modify: true
 ```
 
 There are more ways to customize how you run WebDAV through flags and environment variables. Please run `webdav --help` for more information on that.

cmd/config.go

@@ -14,7 +14,7 @@ import (
 	"golang.org/x/net/webdav"
 )
 
-func parseRules(raw []interface{}) []*lib.Rule {
+func parseRules(raw []interface{}, defaultModify bool) []*lib.Rule {
 	rules := []*lib.Rule{}
 
 	for _, v := range raw {
@@ -22,6 +22,7 @@ func parseRules(raw []interface{}) []*lib.Rule {
 			rule := &lib.Rule{
 				Regex: false,
 				Allow: false,
+				Modify: defaultModify,
 				Path:  "",
 			}
 
@@ -33,6 +34,13 @@ func parseRules(raw []interface{}) []*lib.Rule {
 				rule.Allow = allow
 			}
 
+			if modify, ok := r["modify"].(bool); ok {
+				rule.Modify = modify
+				if modify {
+					rule.Allow = true
+				}
+			}
+
 			path, ok := r["path"].(string)
 			if !ok {
 				continue
@@ -110,12 +118,15 @@ func parseUsers(raw []interface{}, c *lib.Config) {
 			}
 
 			if rules, ok := u["rules"].([]interface{}); ok {
-				user.Rules = parseRules(rules)
+				user.Rules = append(c.User.Rules, parseRules(rules, user.Modify)...)
 			}
 
 			user.Handler = &webdav.Handler{
-				Prefix:     c.User.Handler.Prefix,
-				FileSystem: webdav.Dir(user.Scope),
+				Prefix: c.User.Handler.Prefix,
+				FileSystem: lib.WebDavDir{
+					Dir:     webdav.Dir(user.Scope),
+					NoSniff: c.NoSniff,
+				},
 				LockSystem: webdav.NewMemLS(),
 			}
 
@@ -171,12 +182,16 @@ func readConfig(flags *pflag.FlagSet) *lib.Config {
 			Modify: getOptB(flags, "modify"),
 			Rules:  []*lib.Rule{},
 			Handler: &webdav.Handler{
-				Prefix:     getOpt(flags, "prefix"),
-				FileSystem: webdav.Dir(getOpt(flags, "scope")),
+				Prefix: getOpt(flags, "prefix"),
+				FileSystem: lib.WebDavDir{
+					Dir:     webdav.Dir(getOpt(flags, "scope")),
+					NoSniff: getOptB(flags, "nosniff"),
+				},
 				LockSystem: webdav.NewMemLS(),
 			},
 		},
-		Auth: getOptB(flags, "auth"),
+		Auth:    getOptB(flags, "auth"),
+		NoSniff: getOptB(flags, "nosniff"),
 		Cors: lib.CorsCfg{
 			Enabled:     false,
 			Credentials: false,
@@ -186,7 +201,7 @@ func readConfig(flags *pflag.FlagSet) *lib.Config {
 
 	rawRules := v.Get("rules")
 	if rules, ok := rawRules.([]interface{}); ok {
-		cfg.User.Rules = parseRules(rules)
+		cfg.User.Rules = parseRules(rules, cfg.User.Modify)
 	}
 
 	rawUsers := v.Get("users")

cmd/root.go

@@ -53,9 +53,17 @@ set WD_CERT.`,
 
 		cfg := readConfig(flags)
 
-		// Builds the address and a listener.
-		laddr := getOpt(flags, "address") + ":" + getOpt(flags, "port")
-		listener, err := net.Listen("tcp", laddr)
+		// Build address and listener
+		laddr := getOpt(flags, "address")
+		var lnet string
+		if strings.HasPrefix(laddr, "unix:") {
+			laddr = laddr[5:]
+			lnet = "unix"
+		} else {
+			laddr = laddr + ":" + getOpt(flags, "port")
+			lnet = "tcp"
+		}
+		listener, err := net.Listen(lnet, laddr)
 		if err != nil {
 			log.Fatal(err)
 		}

lib/dir.go

@@ -0,0 +1,83 @@
+package lib
+
+import (
+	"context"
+	"mime"
+	"os"
+	"path"
+
+	"golang.org/x/net/webdav"
+)
+
+// NoSniffFileInfo wraps any generic FileInfo interface and bypasses mime type sniffing.
+type NoSniffFileInfo struct {
+	os.FileInfo
+}
+
+func (w NoSniffFileInfo) ContentType(ctx context.Context) (contentType string, err error) {
+	if mimeType := mime.TypeByExtension(path.Ext(w.FileInfo.Name())); mimeType != "" {
+		// We can figure out the mime from the extension.
+		return mimeType, nil
+	} else {
+		// We can't figure out the mime type without sniffing, call it an octet stream.
+		return "application/octet-stream", nil
+	}
+}
+
+type WebDavDir struct {
+	webdav.Dir
+	NoSniff bool
+}
+
+func (d WebDavDir) Stat(ctx context.Context, name string) (os.FileInfo, error) {
+	// Skip wrapping if NoSniff is off
+	if !d.NoSniff {
+		return d.Dir.Stat(ctx, name)
+	}
+
+	info, err := d.Dir.Stat(ctx, name)
+	if err != nil {
+		return nil, err
+	}
+
+	return NoSniffFileInfo{info}, nil
+}
+
+func (d WebDavDir) OpenFile(ctx context.Context, name string, flag int, perm os.FileMode) (webdav.File, error) {
+	// Skip wrapping if NoSniff is off
+	if !d.NoSniff {
+		return d.Dir.OpenFile(ctx, name, flag, perm)
+	}
+
+	file, err := d.Dir.OpenFile(ctx, name, flag, perm)
+	if err != nil {
+		return nil, err
+	}
+
+	return WebDavFile{File: file}, nil
+}
+
+type WebDavFile struct {
+	webdav.File
+}
+
+func (f WebDavFile) Stat() (os.FileInfo, error) {
+	info, err := f.File.Stat()
+	if err != nil {
+		return nil, err
+	}
+
+	return NoSniffFileInfo{info}, nil
+}
+
+func (f WebDavFile) Readdir(count int) (fis []os.FileInfo, err error) {
+	fis, err = f.File.Readdir(count)
+	if err != nil {
+		return nil, err
+	}
+
+	for i := range fis {
+		fis[i] = NoSniffFileInfo{fis[i]}
+	}
+	return fis, nil
+}

lib/user.go

@@ -11,6 +11,7 @@ import (
 type Rule struct {
 	Regex  bool
 	Allow  bool
+	Modify bool
 	Path   string
 	Regexp *regexp.Regexp
 }
@@ -26,23 +27,24 @@ type User struct {
 }
 
 // Allowed checks if the user has permission to access a directory/file
-func (u User) Allowed(url string) bool {
+func (u User) Allowed(url string, noModification bool) bool {
 	var rule *Rule
 	i := len(u.Rules) - 1
 
 	for i >= 0 {
 		rule = u.Rules[i]
 
+		isAllowed := rule.Allow && (noModification || rule.Modify)
 		if rule.Regex {
 			if rule.Regexp.MatchString(url) {
-				return rule.Allow
+				return isAllowed
 			}
 		} else if strings.HasPrefix(url, rule.Path) {
-			return rule.Allow
+			return isAllowed
 		}
 
 		i--
 	}
 
-	return true
+	return noModification || u.Modify
 }

lib/webdav.go

@@ -20,9 +20,10 @@ type CorsCfg struct {
 // Config is the configuration of a WebDAV instance.
 type Config struct {
 	*User
-	Auth  bool
-	Cors  CorsCfg
-	Users map[string]*User
+	Auth    bool
+	NoSniff bool
+	Cors    CorsCfg
+	Users   map[string]*User
 }
 
 // ServeHTTP determines if the request is for this plugin, and if all prerequisites are met.
@@ -102,7 +103,9 @@ func (c *Config) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	}
 
 	// Checks for user permissions relatively to this PATH.
-	if !u.Allowed(r.URL.Path) {
+	noModification := r.Method == "GET" || r.Method == "HEAD" ||
+		r.Method == "OPTIONS" || r.Method == "PROPFIND"
+	if !u.Allowed(r.URL.Path, noModification) {
 		w.WriteHeader(http.StatusForbidden)
 		return
 	}
@@ -111,15 +114,6 @@ func (c *Config) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		w = newResponseWriterNoBody(w)
 	}
 
-	// If this request modified the files and the user doesn't have permission
-	// to do so, return forbidden.
-	if (r.Method == "PUT" || r.Method == "POST" || r.Method == "MKCOL" ||
-		r.Method == "DELETE" || r.Method == "COPY" || r.Method == "MOVE") &&
-		!u.Modify {
-		w.WriteHeader(http.StatusForbidden)
-		return
-	}
-
 	// Excerpt from RFC4918, section 9.4:
 	//
 	// 		GET, when applied to a collection, may return the contents of an